Various means were used in the prior art to generate a target system which could evaluate the performance of new shooters, weapons and/or ammunition. The problem with prior art systems was that they frequently required targets of large physical size which were expensive to make, install, remove and store. The prior art systems lacked the ability to easily determine ballistic accuracy, shot dispersion, and controllability of the weapon system being tested.
In the past once a physical target was used very little remained, which could be reused inasmuch as the support structure thereof, often including telephone poles, was typically destroyed.
Another problem with prior art system is that large physical targets require special material handling equipment to build, erect and remove. In addition, valuable time is consumed in the scoring, recording and storage of test results. Also, considerable time and equipment is used in the repair and/or replacement of targets between the firing by successive groups of shooters and of various weapons and/or particular lot numbers of ammunition.
When smaller targets were used, in an attempt to conceal the physical target from gunner until a specific instant in time, the cost of raising/lowering or rotating the target was considerable and the eventual destruction of the target and its support was likewise nonproductive. These concealment means are unnecessary with and are eliminated by the synthesized target system (STS).
Prior art photographic means are likewise tedious, time consuming and do not provide immediate results in identifying projectile trajectory information. The present invention provides real-time, objective data at much less cost in capital equipment, and in personnel time used in data reduction.
Another problem with physical targets relates to the inability to photograph a projectile's flight trajectory in the proximity of physical targets due to obscuration. This problem relates to the impossibility of attempting to photograph the round, or rounds, continuously on the axis of the trajectory from a "safe" distance down-range. Prior art systems use a multiplicity of cameras, requiring extreme care in synchronization, and the use of many feet of film in redundant coverage from up-range, ahead of the physical target locations, and augmented by additional camera coverage down range after the physical target, in order to capture post-target break through of the projectile.
The prior art is represented by such patents as U.S. Pat. No. 3,025,406 (1962) to Stewart et. al. entitled, Light Screen for Ballistic Uses. The invention of Stewart serves merely to identify the passage of a projectile through a light curtain. In contrast, the present synthesized target system simultaneously detects and can record the position of projectiles within a target plane and can determine the order in which simultaneous groups of rounds penetrate the target plane, and even can detect and record their order and orientation during penetration. Also, it is noted that two closed-form complete frames or planes are required for operation of the Stewart system, while only one corner of a frame or target plane is required in the present invention.
Other prior art of interest includes U.S. Pat. No. 3,846,026 (1974) to Waters, entitled Rotating Beam Surveying Method and Apparatus; U.S. Pat. No. 3,603,691 (1971) to Hamilton, entitled Laser Control for Automatic Alignment of Structures; and U.S. Pat. No. 3,617,134 (1971) to Frush, entitled Optical Image Frame Coordinate Data Determining System.
The present invention may be viewed as a response to a long felt need for a system which can compare the performance of personnel, weapons, and/or projectiles, having varying characteristics, individually or in combination, and under varying environmental conditions.